Low frequency RFID devices may be used to identify farm animals. The RFID device is interrogated (read) by a suitable reader that incorporates an antenna.
A number of problems can arise where the interrogation occurs as animals move through a stock race. Animals may baulk upon seeing a tag reader above the race, and may hesitate, run backwards, or jump out of the race. As well as causing race inefficiency, the animals may be hurt or undesirably stressed by this process.
A further problem that can occur in animal identification systems is that two or more animals' heads, and therefore also their tags, may enter or be present in a read zone of an antenna at the same time. This can cause a tag collision and may result in one or more tags not being read. This can occur when animals follow each other too closely or when animals do not move through the reader in single file, and is especially a problem with a mixture of different sized animals.
The present invention may provide an improved antenna apparatus, or may at least provide the public with a useful choice.